Thermal fabric



Jan. 8, 1 9 46. R. J. FITZMAURICE 2,392,470

' THERMAL FABRIC Filed Sept, 11, 1943 ATTORNEY Patented Jan. 8, 1946 UNITED STATES PATENT orrlcs THERMAL FABRIC Richard J. Fitz Maurice, Orange, N. J., assignor to Therm-A-Mode Company, Inc., Paterson, N. 5., a corporation of Delaware Application September 11, 1943, Serial No. 501,942

4 Claims.

The present invention relates to thermal textiles of the type in which a heating element consisting of a conductive wire or strand is knitted as part of the fabric itself. More particularly, it contemplates the provision of a knitted fabric from which heating pads, garments, blankets,

rugs, and the like, may be fashioned, the fabricbeing capable of being cut to pattern of the garment or other article as desired without breaking the circuit necessary to deliver the temperature for the purpose for which the article is intended.

Electrical heating pads and similar articles are well known in the art and in some cases the electrical wires forming the heating circuit are actually embodied in the textile. Often, however, in articles of this sort, the textile forms a mere foundation upon which the wires are sewed as an independent element, and the whole is enclosed in a slip or casing of some suitable fabric,

Articles of this sort may include heating pads, blankets, floor rugs, or warming garments for use by aviators at high altitudes.

It is generally desirable in utilizing thermal fabrics of 'the kind described for fashioning heating appliances that different regions or zones of the device should have means for controlling the delivery of different degrees of temperature to previously been necessary to include various de-- vices such as rheostats, thermostats, and the like, in the circuits of the garment, pad, blanket, etc., and sometimes these are even embedded in the fabric itself.

It is'an object of the present invention to provide a thermal fabric capable of being fashioned into a garment, pad, blanket, mat or other similar article having capacity for delivering a desired temperature without the use of auxiliary heat controlling apparatus such as thermostats, rheostats and the like. H

It is a further object of the present invention to provide a textile fabric into which the heating having the woof composed of yarn and wire formwise fashioned without breaking the continuity of the wire forming the heat circuit.

It is a further object of the invention to provide such a fabric so knitted that various circuits are provided which are capable'of delivering different temperatures to different parts of the article, and heat control is effected by the number and length of wire turns laid in to the inch of length of the fabric and by bridging and splitting the amount of current and voltage supplied.

It is a further object to provide a thermal fabric ing the heating element bound together by warp threads of cotton, linen, silk, or the like knitted through the woof.

According to the present invention, a fabric is fashioned by means such as knitting in which the woof is composed of yarn of wool, chenille and the like. Into and as part of the woof is worked a resistance wire, preferably stranded and insulated preferably with a resinous material though fibrous coverings are generally sufllciently effective for insulation. The warp may be composed of thread of cotton, silk or the like if a tight fabric is desired; or it may also be of yarn if a looser fabric is more adaptable to the purpose in view. The fabric yardage i made up of panels, each panel containing a wire pattern which is continuously repeated in other panels, which are separated by headers" and which may be cut through without severing the wire circuit pattern.

A knitted fabric of the invention may be made in the following manner: A length of yarn may be laid in the woof, as, for instance, before the needles of a knitting machine. The needles engage the warp threads forming knots around the length of yarn thread laid in the woof. This operation is repeated for a predetermined number of turns of threads, or kicks, as they are termed, of the yarn and then the wire properly insulated is laid in. A given kick of the wire may extend wholly across the fabric or only partially across according to the use for which the fabric is intended. The wire is knitted in by the warp threads in the same manner as the yarn. The length and diameter of the wire, its composition and the number of strands control the temelement is knitted as an integral part of the perature of thefabric without the use of auxiliary devices.

The invention further contemplates the provision of yardages of the fabric into which a resistance wire is knitted in a predetermined pattern that is suitable for delivering adequate heat fabric but which may be cut, tailored or other to a particular part of a garment or other article designed to provide heat. I use the term "yardage" to indicate an indefinite length of material of a width suflicient to contain the wire pattern with suflicient unwired margin to permit cutting and fashioning the particular article intended. Thus, for example, a yardage of fabric containing the heating element of one side of a sleeve of an aviators heating jacket may be knitted with the' wire running continuously through the whole length of the yardage in a pattern repeated over and over again in panels, each of a length suitable for fashioning a sleeve. Similarly, a. wire pattern for the back or front of a jacket may be knitted in panels into the fabric. In each of these panels, however, the wire occupies an area of the fabric that is more or less centered in the width of the material, leaving an unwired space on either side of'the circuit pattern that can be cut through without severing the wire. The yardage may be manufactured in long lengths containing material suflicient for a. large number of articles and may be rolled into a bolt and supplied in this manner to the trade.

In the drawing to which reference is now made, the invention is illustrated as it is applied to an aviation heating garment and to a rectangular heating pad or the like although it is to be understood that a pad or blanket heating element may be of another shape than rectangular.

Fig- 1 represents a part of a yardage of the fabric of the invention having knitted therein a pattern of resistance wire that is adapted to the f hi n of one side of a sleeve, the pattern being repeated in successive panels of which tw are shown.

Fig. 2 shows one sideof a sleeve fashioned from the fabric of Fig. 1.

Fig. 3 illustrates one panel of a knitted fabric adapted for use in a heating pad, blanket or the like of rectangular shape.

' Fig. 4 is a detai1 showing the method of knitting, there being six kicks of chenille to one kick of wire.

Referring now to Fig. l, a broken length of yardage of the knitted fabric of the invention is illustrated. The fabric I is composed-preferably from chenille yarn and insulated wire preferably stranded, and .may be fashioned on appropriate machines in indefinite lengths. Into the woof of this fabric a continuous wire is laid in in a continuously repeated pattern, two panels being shown in the figure with the wire pattern repeated at 2 and 3. Both yarn and wire are bound together by knitting the warp threads through them. Between each panel containing the pattern headers are knitted, i. e., portions of the fabric in which the wire is brought out to the full width of the fabric, as shown at A, B and C. Patterns 4 of one side of 'a sleeve of an aviation garment is indicated in dotted lines on each panel,.from which it will be seen that the wire pattern lies wholly within the dotted sleeve pattern and wlren the panels of the fabric are severed onthe line 1-1 and the Panels are then cut'to the sleeve pattern, the wire remains unbroken except at the "headers" A, B and C.

In Fig.2 is shown one side of a sleeve 5 as cut on one of the patterns I of Fig. 1, It will be ob- 6 to prevent the fabric from fraying after the sleeve is out.

It will be evident that the sleeve side illustrated will be adapted to deliver a. predetermined temperature and that this temperature will be determined by the total length of the wire, the material of the wire and its diameter or in thecase of a stranded wire the number of strands and size of the wire in the strands. On a knitting machine the chenille yarn is fed to the needles and a predetermined number of turns of yarn are laid and knitted in, and then one turn of wire. These turns or kicks may be greater or less in number in accordancewith the amount of wire to be included in the circuit. Ihe greater the number of'kicks of chenille, the less will be the number of "kicks of wire, and consequently the less will be the amount of heat delivered.

The wire is fed to the needles in the samemanner as the yarn. However, in the pattern shown in Fig. 1, the wire occupies only a middle region of thefabric. This-wire pattern is effected by blocking th wire feeding mechanism so that the wire feed movement will be less in either direction across the fabric than the feed movement of the yarn.

In Fig. 3 is shown a panel of the fabric of the invention cut to ectangular shape for use as a pad or blanket in which the wire 8 coated with a suitable insulation is extended through the entire width of the material and the headers A and B are shown stripped to form pigtails to be connected to a source of supply of electric current.

Fig. 4 is a detail of the fabric of the invention showing the yarn and wire somewhat enlarged fo clarity with the center of the panel broken away. As represented in Figs. 3 and 4, there are six kicks" of chenille yarn 9 to one kick 8 of the insulated wire. The whole is bound together 40 by the knitted warp threads I 0.

served that-the wire arrangement 2 is wholly of current. The edge of the'sleeve is bound as at While Figs. 3 and 4 are shown chiefly for the purpose of illustrating the method of knitting, a

fabric such as illustrated in these figures may be used to form part or all of a garment, heating pad, blanket, mat or rug, and a wire pattern may be worked in in a manner suitable to the amount of heat to be delivered. In all the figures it will be understood that the turns or kicks of yarn and wire from the woof of the fabric and that they are bound in by knitting the warp threads through Having thus described my invention, what I claim is:

l. A thermal fabric comprising a woof of chenille yarn and insulated wire bound together by knitted warp threads, said wire b'eing knitted in a pattern to provide a heating element and said pattern repeated continuously throughout the length of said fabric.

2. A thermal fabric comprising a woof of yarn and resistance wire bound together by knitted warp-threads, the yarn threads having a, plurality of .turns to each single turn of wire and said wire being laid in in a pattern centered in said fabric and continuously and eonnectedly repeated throughout the length or said 'iahric, the 3 number and length of the turns 01- said wire being determined by the degree of temperature desired, and unwired portions of fabric outside said wire pattern that may be cut through and fashioned to a desired shape without cutting the wire of said W vide heating elements for other parts oigarments to be tailored into complete garments with electrical circuits capable of delivering, when energized, dmerent temperatures to different parts of said garments, said fabrics being knitted in yardaz s of indefinite l l h and each 0! said wire Pamms g. repeated connectedly and continuously in successive panelsthroughout the length 01 said yardage. i

4. A'thermal fabric comprising a woofof yarn and wire bound together with knitted warp threads, said wire being laid in in a pattern with electrical circuits capable of delivering, when energized, predetermined temperatures to said pattern, said fabric being knitted in yardages of indefinite lengths and said wire pattern being repeated connectedly and continuously in successiva panels throughout the length of said yardage, the connecting wires between patterns being woven into the spaces between panels.

RICHARD J. FITZ MAURICE. 

